It started out as a tiny bump on her forehead. Maybe a pimple, she thought, although at 65, she was a tad old for it. But the bump stayed and stayed and stayed. And it changed in shape over time, becoming asymmetrical.

Finally, about a year later, our friend figured she should go to her dermatologist, Dr. Richard Castiello, to have it checked out. When the doctor's nurse took her into the exam room, she murmured, "Oh, oh." That was our friend's second hint that this was no ordinary pimple.

The doctor examined her and said he wanted to remove the bump immediately and send it in for a biopsy. And he did, right then and there.

It took some time, too, as the doctor wanted to be thorough and clear the whole area out. He added that it looked like an early form of basal cell skin cancer, the noninvasive kind.

The doctor also stated that it's not unusual for people to develop skin cancer as they grow older. It's the accumulation of sun damage over time. He warned that it was important to have her entire body checked annually for other skin cancers. They can develop anywhere.

When our friend returned to find out the result of the biopsy, the doctor confirmed that the bump was a basal cell carcinoma. It's the least worrisome kind of skin cancer.

Basal cell and squamous cell skin cancers are the most common. They grow slowly and are highly treatable, it said in the April issue of the Mayo Clinic Health Letter.

Now our friend has an interesting white scar above her right eyebrow, which she doesn't mind. People who have had skin cancer often have the telltale scar on their faces. Some people will opt for a plastic surgeon to hide it.

Skin cancer incidences are growing exponentially. Doctors aren't entirely sure why, though they know it's often caused by excessive exposure to the sun. It's sneaky, too. It usually doesn't show up until years after a person has suffered through a sunburn.

"Melanoma tends to be more serious, with the greatest likelihood of spreading (metastasizing) to other body tissues," the newsletter said.

Skin cancer also is partial to families. If your mother or aunt had skin cancer in their later years, you are at risk for it.

But there's a lot you can do to prevent skin cancer. First, stay out of that glorious-looking sun! Especially when the sun is strongest - between the hours of 10 a.m. and 4 p.m.

When you take your grandchildren to the beach or the zoo, start slathering sunblock on them and yourself at least a half-hour before going into the sun. Use the highest SPF lotion available. One ounce, or about the amount that fits in a shot glass, should be used each time - enough to block both the ultraviolet-B and the UVA rays.

Encourage everyone, young and old, to wear hats that cover their heads, even in the wintertime. It's amazing how bad even the winter sun is for our skin.

Warn your teenage grandchildren about the perils of those beautiful-looking suntans. Tell them that more than half of newly discovered cancers in this country are skin cancers. And there's been a sharp increase in its occurrence in baby boomers as they grow older.

They probably won't listen - it's a summer ritual for teens to see who can get the best-looking tan.

Remember that hilarious comic strip sequence some years ago in "Doonesbury"?

It starred Zonker, a young man whose goal in life was to win - and to keep winning - the contest for having the best suntan each summer at the beach. And he did, for several years in a row.

Today, "Doonesbury" has gotten religion. Not too long ago, a strip had Zonker showing a teen his trophies, but complaining about the many hours he'd spent in the contests because they were too dangerous.

Keep in mind that the chances of developing skin cancer are far more likely for anyone who's had five or more sunburns. And it doesn't respect older people: those in their 60s and 70s can burn their way to skin cancer.